Clinical Findings, Treatment Recommendations, and Outcome in Dogs Following Ingestion of a Single Unintended Dose of Trilostane: 403 Cases (2008–2023)

OBJECTIVE: To characterize the clinical signs and outcomes in dogs following ingestion of a single, unintended dose of trilostane. The secondary objective was to describe treatment recommendations given for this population. DESIGN: Retrospective evaluation of cases of canine trilostane exposure from February 2008 to August 2023. SETTING: Private, specialty toxicology consultation service. ANIMALS: Four hundred three cases were selected from the American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Poison Control Center AnTox database using a nonstratified sampling technique. Data included patient demographics, history, therapeutic use of trilostane, exposure history, diagnostic findings, treatment recommendations, and outcome. INTERVENTIONS: None. METHODS AND MAIN RESULTS: The most common cause of trilostane exposure was ingestion of another dog's prescription (248/403 [61.5%]), followed by ingestion of extra or excessive dose(s) of the dog's own prescription (147/403 [36.5%]). Forty-one dogs (41/403 [10.2%]) had clinical signs attributable to trilostane exposure. Median onset of clinical signs after exposure was 2.5 h (range: 0.25-72 h). The most frequently reported clinical signs were vomiting (17/41 [41.5%]), lethargy (15/41 [36.6%]), and diarrhea (7/41 [17.0%]). Four cases (4/403 [0.99%]) were reported to require veterinary treatment for trilostane toxicosis. Of the cases with follow-up from the ASPCA (200/403 [49.6%]), most dogs (188/200 [93.5%]) developed no clinical signs from acute trilostane exposure. The median exposure dosage (13.2 mg/kg) in the 12 dogs that developed clinical signs was significantly higher than in those that did not (3.3 mg/kg). CONCLUSIONS: The current study suggests that dogs ingesting a single, unintended dose of trilostane are likely to experience mild, self-limiting signs. The need for extensive hospitalization or aggressive medical care is unlikely, even with high single doses that exceed the published and Food and Drug Administration-approved therapeutic dosage.